1. Technical Field
The present disclosure relates to a turbo-compressor and a refrigeration cycle apparatus including the turbo-compressor.
2. Description of the Related Art
There is so far known a technique for suppressing the occurrence of erosion that is caused by a liquid having accumulated on a casing surface of a turbo-compressor. Japanese Unexamined Patent Application Publication No. 8-233382 discloses a turbo-refrigerator in which a heating device for a gas coolant inlet into a turbo-compressor is disposed in an inlet pipe of the turbo-compressor. The heating device is disposed in the inlet pipe at a position nearer to an evaporator than an inlet vane.
Japanese Unexamined Patent Application Publication No. 2009-85044 discloses a turbo-compressor including an open-type impeller, a casing, and a heating means for heating the casing. Because the heating means heats the casing, a main flow of steam is suppressed from being condensed upon contact with the casing.
Japanese Patent No. 4109997 discloses a turbo-compressor including an inlet vane. According to Japanese Patent No. 4109997, the flow rate of a working fluid inlet through an inlet of the turbo-compressor is controlled in accordance with the opening degree of an inlet guide vane that is disposed at the compressor inlet.
In the related-art turbo-compressor, however, it is demanded to increase a degree of superheat of the working fluid inlet into the impeller, and to improve durability of the turbo-compressors.